The principle objective of the Clinical Core will be to maintain a panel of 375-400 volunteer patients and controls at the ADRC, and 100 volunteer patients & controls as part of our Hispanic initiative at our satellite clinic in Chula Vista, and to recruit new D subjects with a mild degree of cognitive impairment (defined as DRS>109, many of whom will leave MMSE >24/30 to replace subjects who have become more impaired. During the period of this competing renewal we will increase our recruitment of specific groups of patients and controls to meet research needs. Particular emphasis will be to recruit controls over the age of 80 in order to meet the need for a greater number of autopsies of elderly control brains for clinical-pathological correlations and to meet for a greater number of autopsies of elderly control brains for clinical-pathological correlations and to meet the needs of those studying genetic markers (since the effect of Apo-Eepsilon4 as the major susceptibility factor for AD diminishes after age 80). Annual participant evaluations will include demographic, historical, medical, neurological, psychiatric and neuropsychological examinations to aid in diagnosis and to track yearly changes in cognitive and neurological progression. The evaluations provide a behavioral data base that can be used by the various research projects associated with the ADRC and in addition, provide detailed longitudinal data on the course and progression of AD. The Clinical Core maintains banks of fibroblast cultures, DNA, plasma samples, and CSF that are used by a variety of investigators. The Clinical Core provides the sources that permits participation multicenter trials and collaboration data and genetic analysis, as well as supply a well characterized cohort to other D investigators in San Diego. Finally, developmental work will be undertaken to improve our ability to diagnose AD early and to improve the diagnosis of other dementias such as dementia associated with Lew bodies and fronto-temporal dementia.